I hired out (Fort Worth, TX 1988) and had to go through orientation.
One of the instructors was a "yard sale" geek and an old Georgia boy. Told him I was a 16 gauge geek.
Said he bought a chest of drawers earlier that had a butt load of 16 gauge ammo in it, would I like to have it!
"Heck yeah!"
The next day he handed me a small bathroom sized garbage can with +/- four boxes of 16 gauge ammo.
It was a mixture of high brass #7.5's and low brass #8 field loads.
The stuff looked to be several years old in 1988!
....and I'm still using the stuff. 😉

So, there you have it! I turkey hunt with 30+ (35?) year old 16 gauge ammo I dug out of a garbage can.
The "kill" was the fall of 2018.